农产品与环境中持久性有机物污染研究现状及存在问题

环境和农产品污染问题已受到各国政府和公众的持续关注,针对持久性有机污染物污染现状及存在问题进行综述,为持久性有机污染物污染的防治提供参考依据。     

多溴联苯醚污染现状研究进展

多溴联苯醚(PBDEs)是一种新增的环境持久性有机污染物,作为一种溴代阻燃剂被广泛地应用于日常生活中。近年来在世界各地区多种环境介质和人体中均检测到PBDEs的存在,其中电子垃圾拆解区、污水处理厂排水口处及大型工业区附近PBDEs污染最为严重。由于PBDEs具有生物累积性、环境持久性及生物毒性等特性,其引起的环境及健康问题受到广泛的关注。笔者沿着水体-沉积物-食用动物-人体和大气-人体这两条链,综述了近年来环境介质和人体中多溴联苯醚的污染现状、污染来源、生物富集特征以及人类膳食和日常生活中PBDEs的暴露情况,并进行了国内外污染水平对比,从而分析了中国目前所存在的问题,提出相应对策建议,以期为中国深入开展PBDEs环境毒理学和生态风险评估等研究工作提供参考。     

国务院提请全国人大常委会审议批准《〈关于持久性有机污染物的斯德哥尔摩公约〉新增列硫丹修正案》议案

<正>本刊讯8月26日下午,在十二届全国人大常委会第四次会议第一次全体会议上,受国务院委托,环境保护部部长周生贤作了关于提请审议批准《〈关于持久性有机污染物的斯德哥尔摩公约〉新增列九种持久性有机污染物修正案》和《〈关于持久性有机污染物的斯德哥尔摩公约〉新增列硫丹修正案》议案的说明。2011年4月,在瑞士日内瓦举行的《斯德哥尔摩公约》第五次缔约方大会上,     

中国持久性有机污染物削减有了行动纲领 将统一处置和管理废弃库存POPs农药

<正>本刊讯1月24日《,国家履行斯德哥尔摩公约工作协调组协调员会议》在北京召开,国家环保总局、发展改革委、外交部、财政部、商务部、科技部、农业部、卫生部、建设部、海关总署和电监会等11个部门参加了会议。会议讨论和审议并且原则通过了《中国履行〈关于持久性有机污染物(POPs)的斯德哥尔摩公约〉国家实施计划》。这表明我国持久性有机污染物削减有了行动纲领。     

5.17,三氯杀螨醇在中国寿终正寝

<正>5月17日,中国唯一的三氯杀螨醇生产线在江苏扬农集团正式关闭,此举标志着三氯杀螨醇在中国全面停产。这是一个值得记入中国农药发展史的日子,中国作为发展中国家,本着对人类赖以生存的环境高度负责的积极态度,兑现了自己对世界的承诺。这是中国履行《关于持久性有机污染物的斯德哥尔摩公约》,减少和消除持久性有机污染物方面取得的又一重大进展。据悉,农业部在今年发布公告,将对目前市场上7种高毒农药逐步实行限管和退市政策,对高毒农药定点经营、实名制购买示范和低毒、低残留农药示范补贴工作。因此,我国正在加速高毒农药的淘汰。     

中国全面停产三氯杀螨醇

<正>本刊讯滴滴涕(DDT),作为三氯杀螨醇生产的中间原料,早在2001年就被列入《斯德哥尔摩公约》受控的持久性有机污染物(POPs)之一。5月17日,中国唯一的三氯杀螨醇生产线在江苏扬农集团正式关闭,标志着三氯杀螨醇在中国全面停产。三氯杀螨醇是一种防治棉花、果树、花卉等作物上螨类的杀虫剂,因其杀螨效果明显,且价格低廉,曾受广大农户青睐。然而持久性有机污染物DDT在三氯杀螨醇生产过程中作为中间原料使用,造成三氯     

土壤多环芳烃污染修复技术研究进展

多环芳烃作为环境中典型的持久性有机污染物,因其毒性强、危害大而备受关注。本文从生物修复、物理修复和化学修复等方面,概述了近年来国内外土壤多环芳烃污染的主要修复技术。生物修复技术处理成本低、操作便捷、二次污染小,但修复周期长、不适用于高浓度污染土壤;物理修复和化学修复可用于高浓度污染土壤,但存在改变土壤原有结构、运行和维护成本高等缺点。针对高浓度PAHs污染土壤,首先宜采用物理和化学修复去除其中大部分污染物,再进一步利用生物修复进行无害化处理,实现污染土壤的循环利用。     

斯德哥尔摩公约签署10年取得长足进展 中国POPs污染防治基本达标

<正>本刊讯今年是中国签署《关于持久性有机污染物(POPs)的斯德哥尔摩公约》10周年。11月11日,在公约对中国生效7周年之际,公约签署10周年纪念大会在北京隆重举     

履行斯德哥尔摩公约国家实施计划启动 削减有机污染物农药任务最重

<正>本刊讯随着"中国履行斯德哥尔摩公约国家实施计划"的启动,一份削减控制淘汰持久性有机污染物(POPs)时间表摆在了农药企业面前。     

POPRC15和CRC15在意大利召开

<正>从农业农村部农药检定所了解到,《关于持久性有机污染物的斯德哥尔摩公约》持久性有机污染物审查委员会第15次会议(POPRC15)和《关于在国际贸易中对某些危险化学品和农药采用事先知情同意程序的鹿特丹公约》化学品审查委员会第15次会议(CRC15)于10月1-10日在意大利罗马召开。巴塞尔、鹿特丹、斯德哥尔摩三公约执行秘书帕耶先生出席会议并致辞。POPRC15会议审议通过了全氟     

Accumulation and the Harm of POPs to Organisms Lived in Lakes

The recent works about the accumulation and the harm of persist organic pollutions (POPs) to organisms lied in are widely distributed in lake ecosystem, transferred and biomagnified from prey to predator through pelagic and benthic food web, accumulated in high lipid organ, and increasing concentrations with the increasing of lipid content, age and body length. Until now, the present of POPs in lake ecosystem still has harmful effects to aquatic organism of lakes and can transfers to people through eating fishes from lakes and has some negative effects to human health.     

多溴联苯醚在环境中的残留及毒理学效应研究进展

[目的]持久性有机污染物(POPs)是导致环境污染的重要原因,其中多溴联苯醚(PBDEs)又是POPs中的一种,所以全面了解多溴联苯醚在环境中的残留及其对生物体的毒理学效应对于环境的治理和人的健康至关重要。[内容]本文简要归纳了多溴联苯醚在土壤、水体中的残留和相互之间的迁移、转化,总结了多溴联苯醚对生物体的急性毒性和生理生化毒性,并分析了多溴联苯醚对生物体抗氧化系统、机体组织器官的和生物遗传的影响,对接下来进一步的研究提供了依据。[建议]针对多溴联苯醚在环境和生物体中具有高毒性的问题,提出了通过制定更加严格的法律法规来限制多溴联苯醚的使用、加强对含多溴联苯醚废弃物的处理,禁止进口电子垃圾,选取距离居民区较远的地方进行生产等措施,并对发展新型溴代阻燃剂进行了展望。     

CFD-DEM Simulation to Study the Filtration Characteristic of the Fine Particle in the Filter Media

The gas-solid two-phase flow characteristics of fine particles in the filter media were simulated based on CFD-DEM (Discrete Element Method) in this study, and the particle group, particle size distribution, and the rebound effect between particles, particle and fiber were taken into account the calculations. Additionally, the movement characteristics of the particle group and the deposition form of the fine particles in the fibrous filtration were analyzed. The results indicate that it is convenient and feasible to simulate the filtration process of the filter media as well as the deposition process and form of the fine particle on the media surface using CFD-DEM, and the simulation results are consistent with the experimental observations in the literature. The surface filtration has larger contribution to the filtration process, and most of the particles are captured by the media surface. Meanwhile, parts of smaller particles that enter into the media are captured by the depth filtration. A larger number of particles are collected by the particle-particle capture mechanism. The filtration efficiencies of the filter media are varied with the particle systems, and for the model of the filter media in this study, the filtration efficiency of the multi-particle system is about 20% higher than that of the single-particle one.     

Time Domain BEM for Wave Propagation Problems in Layered or Anisotropic Media and Its Application in Engineering

The dynamic response of an underground powerhouse under seismic waves is studied by time domain BEM for anisotropic media. The responses of displacements and stresses are evaluated. The effects of angle and frequency of incident waves and the degree of media anisotropy on dynamic response of the underground structure are analyzed in detail. Some important findings for engineering are obtained.     

Wave Propagation Behavior in Saturated Porous Media

In this paper, an attempt is made to discuss the wave propagation behavior in saturated porous media with the decomposition of the motion equations. And it is denoted that there are two types of dilatational waves and one rotational wave. Also, the motion equations of the different waves are obtained, and the wave velocities in some special cases are calculated, from which it is concluded that permeability of media greatly affect wave propagation behavior.     

文冠果工厂化育苗组织培养技术体系建立

文冠果(Xanthoceras sorbifolia Bunge)是中国特有的一种抗旱耐盐的油料绿化树种,千花一果、植株变异大;扦插、嫁接等无性繁殖方式受母株繁殖材料数量和质量限制,组织培养尚存在不定芽增殖系数低、生根困难、试管苗移栽成活率低等问题。本研究基于植物组织培养进程5个阶段,分别研究其关键技术,发现文冠果茎段以有效氯浓度1.0%的二氯异氰尿酸钠水溶液消毒20 min去污染率最高,达46.7%。不定芽在添加6-苄氨基嘌呤0.8 mg/L、吲哚-3-乙酸0.05 mg/L、蔗糖30 g/L的MS培养基上培养30 d,增殖系数达5.22;在IBA 1.0 mg/L的1/2MS草炭、珍珠岩等比例混合基质上培养30 d,生根率达73.3%;在相同处理的琼脂培养基上的生根率为60.0%;在相同处理的琼脂培养基上培养15 d后,转接至活性炭琼脂培养基上培养15 d,生根率为56.7%。混合基质和琼脂培养基上的小植株驯化成活率分别为93.3%和83.3%。本研究为文冠果组织培养工厂化育苗微型快繁技术体系的建立提供基础。     

农村受众在当前大众媒介中话语权现状及影响因素分析

为探索农村受众在当前大众媒介中话语权现状、影响因素。以东北地区农村受众为研究对象,通过对其发放问卷进行抽样调查的形式,从农村受众对媒体的信任度、运用媒介话语权的能力和媒介话语权意识方面进行分析。研究表明,农村受众在当前大众媒介中尚处于话语权缺失的状态,农村受众对媒体的信任度、运用媒介话语权的能力、媒介话语意识是主要影响因素。研究发现农村受众的媒介话语权需整体提升。     

国内农业核心期刊新媒体应用现状分析

统计分析国内农业核心期刊新媒体应用数据和《中国科技期刊引证报告》(2015年版)农业核心期刊影响因子,旨在为新媒体环境下农业科技期刊发展策略研究提供支持。研究发现,农业核心期刊新媒体应用总体上呈现出"分散"的特点;不同学科新媒体的应用存在较大的差距;在同一学科中,应用新媒体的农业核心期刊的影响因子比未应用新媒体的期刊高。农业核心期刊新媒体应用现状拓展了科技期刊新媒体应用研究,为新媒体应用策略研究提供基础支持。新媒体应用有效提升农业核心期刊的影响力,将成为今后农业核心期刊影响力提升的主要措施。     

Secondary somatic embryogenesis and applications in plant breeding

Summary Secondary somatic embryogenesis is the phenomenon whereby new somatic embryos are initiated from somatic embryos. Such cultures have been described in at least 80 Gymnosperm and Angiosperm species. In the initial step (primary somatic embryogenesis) such cultures have to be started from plant explants. In general, primary somatic embryogenesis from vegetative plant explants is, indirect and mostly driven by auxin (AUX) or auxin and cytokinin (AUX/CYT) supplemented media, whereas, from zygotic embryos it is direct and driven, to a larger extent, by CYT or growth regulator free media. Primary somatic embryogenesis from floral plant explants is between these two extremes. Indirect and direct somatic embryogenesis should be seen as two extremes of one continuum: in indirect somatic embryogenesis the embryos develop up to the (pre)-globular stage and in direct somatic embryogenesis to mature stages before they are subjected to secondary embryogenesis. In general, secondary embryogenesis requires no growth regulators in species with CYT driven primary embryogenesis. Whereas, continuous exposure to growth regulators is needed in species with CYT/AUX or AUX driven primary embryogenesis.In most species somatic embryos can be converted into shoots, although the frequencies are mostly low. In general, somatic embryos induced by growth regulator free or CYT supplemented media meet more difficulties in shoot development than embryos induced by AUX supplemented media. Applications of secondary somatic embryogenesis for plant breeding are discussed.     

A New Method of Separating the Shear Waves Splitting in Anisotropic Media

For azimuthal anisotropy seismic exploration, it is very important to separate the fast and slow shear waves splitting in this type of anisotropic media. Many researchers have worked on this problem, but their methods are not realistic in exploration. In this paper, a new method of separating the shear waves splitting in EDA media is presented, that can be directly applied to actual use. Through numerical examples, it can be found that the method is highly efficient and accurate.